USGBC is expanding the coverage on the LEED system into several additional categories including LEED-EB for existing buildings and LEED-CI for commercial interiors. And LEED-H for residential construction is in a pilot phase.

It is interesting that these guidelines were released just before the launch of the USGBC LEED-H rating system. Are the NAHB's guidelines a significant shift toward truly greener homebuilding or is the organization actually jumping on the green bandwagon to undermine the stronger LEED requirements?

On the surface, the two sets of guidelines look very similar. Both have corresponding sections that deal with site, water management, energy efficiency, interior air quality, and so on. The two may be similar because there are local and state guidelines throughout the country that are somewhat uniform, according to USGBC communications director, Taryn Holowka.

But there are differences in several key areas. Holowka says one difference is that the NAHB program guidelines don't require third-party verification, with the exception of HVAC duct testing. She notes: "LEED-H is a certification that is verified independently."

In NAHB's guidelines, "verification" often requires nothing more than referring to the house plans. This lack of independent testing calls into question the effectiveness of the NAHB program. Certifying whether a house meets bronze, silver, or gold requirements is left in the hands of home builders and their local associations.

Size Matters

Another critical difference between the NAHB and USGBC programs is that LEED-H gives more weight to the size of houses. Ten points can be earned for a house that is sized below the national average in its particular category. This could account for as much as one third of the basic certification points.

The NAHB guidelines provide for similar reductions. But LEED-H also subtracts points for houses exceeding the average size, while NAHB imposes no penalty for excess size, effectively allowing builders to skirt the issue altogether.

The gross size of a building affects almost all aspects of its environmental impact. With a smaller total footprint, fewer materials are used, and long-term energy use is significantly reduced.

But with larger houses, builders' profits tend to go up. The average size of an American house has grown from 1400 square feet (130 square meters) 30 years ago to 2200 square feet (205 square meters) today. A sudden size reduction now would be painful for much of the building industry. So, as consumers continue to buy "McMansions," homebuilders keep building oversized houses.

The Official Greenwash

Among the most prominent purveyors of greenwashing these days is the U.S. government. The current administration has shown a propensity for craftily naming legislation like the "Clear Skies" initiative to imply positive environmental qualities that are lacking in reality. Environmental groups say this initiative is weaker than its predecessor, the Clean Air Act of 1970 and in some ways makes it easier for polluters to increase overall emissions.

Bush's recent announcement that "we need to cure our addiction to Mideast oil" was followed by a welcome promise for funding for solar energy research. He said nothing, however, about what is potentially the most significant factor: reducing consumption, or conserving. He apparently maintains his faith that future technology in itself will solve all our environmental problems.

Wetlands Protection?

Environmental groups critical of the Bush administration have also accused NAHB of questionable environmental practices including promoting sprawl. That NAHB has spent large sums to weaken legislation such as the Endangered Species Act lends credence to this perception.

The discrepancy between its words and actions have put NAHB at odds with groups like the Sierra Club. Sierra Club president Carl Pope claims that while NAHB publicly declared itself "a leader in promoting smart growth," it was privately calling upon its members to oppose urban growth boundaries.

On the issue of wetlands, NAHB states: "One common misconception is that we are losing vast amounts of wetlands every year. In fact, studies indicate that we have achieved a 'no net loss' status and we may actually be gaining wetlands."

Yet the sources NAHB supplies to "learn the truth about wetlands" are links to their own press releases and other internal reports, none of which seem to clearly support the claims.

Despite these contradictions, it's important to note that there has been a significant change in NAHB's tone, from not addressing environmental strategies to an emphasis on green building practices. The question remains as to the depth of NAHB's commitment to reducing the enormous environmental impacts of our built environment.

A keystone is the question of verification of green building performance. The only way to ensure that green certification guidelines have real teeth is for the verification process to be independent and unbiased.

Fairmont Square Rowhouses, designed by Ed Waterbury Architect and under construction in Eugene, Oregon, are part of the LEED-H certification process which rewards the efficiency of multifamily housing.Photo: Rainbow Valley Design

Keeping all of the ducts within the heated space of the structure saves energy but also poses challenges in duct routing. At the Fairmont Square Rowhouses, ducting is accommodated in a dropped ceiling in the kitchen.Photo: Rainbow Valley Design

A copper coil recovers about 70 percent of the heat from the shower waste stack, a feature which earns points in both LEED-H and NAHB certification.Photo: Rainbow Valley Design

Whether precious U.S. wetlands are growing or shrinking remains a matter of debate, despite clear evidence of their endangerment.Photo: www.arttoday.com

Even in the very densely populated country of The Netherlands, wetlands are protected by a society that understands their value.Photo: www.arttoday.com

"McMansions," or unnecessarily large, highly resource-consuming houses, have become popular in the United States. Photo: www.arttoday.com